PS Audio FR30 speakers

[Killingbeans]

But we know it sounds better.

Of course it sounds better. But do we know why it sounds better?

Is it because of expectation bias from the larger expenses themselves, or from being told that better sound should be expected? Is it visual bias from seeing gear that "looks the part"? Or is it from an actual improvement of the soundwaves? And in the latter case, what improvements are we talking about, and how do you verify them?

Measurements most definitely tells us that diminishing returns is a real thing.

I saw those wall mounted passive crossovers with ginourmous Duelund capacitors in the 1ET7040SA thread. It looks amazing, and I have deep respect for the time, money and dedication that must have went into it. But all serious investigations I've seen, trying to pinpoint noteworthy benefits from using "high-end" crossover components, have failed to find anything whatsoever. Gorgeous sculpture though*.

If you are presented with zero evidence of something causing an improvement, other than anecdotes, and at the same time have enough understanding of the subject to suspect cognitive bias being at play, is it really blissful ignorance to assume that the improvement was never to be found in the soundwaves to being with?

*Sorry for being snarky. Duelund is on my personal top 10 of companies that makes me want to move to a different planet.

 

[antcollinet]

...you will always get better sound if you spend more. No one can quantify whether something sounds “2X” better. But we know it sounds better.

Another making the mistake of assigning a linear relationship between price and sound quality.

One of the great things about this site is we know exactly when spending more buys better sound quality. More importantly, we know when it doesn't - and also when the relationship between price and quality is inverted.

 

[kemmler3D]

Diminishing returns is a fictitious construct made up by those who cannot, or do not want to, afford spending more. As long as you choose wisely, you will always get better sound if you spend more. No one can quantify whether something sounds “2X” better. But we know it sounds better.

Couldn't just scroll past this comment, because it couldn't be more wrong.

Diminishing returns is a concept exported from economics. It's a fundamental reality in any market where additional labor or technological advancement is needed to produce an incremental improvement. It's a formalized concept based on the common-sense reality that throwing more money at the problem only gets you so far, i.e. that you can't invent new technology solely by spending more.

No, we can't say exactly what a "2x" improvement is, exactly, since quality is subjective. However, I think almost any sane person would agree that if you took the best item at any price point, and graphed performance on the Y axis and price on the X axis, the line would have a decreasing slope, probably something rather logarithmic. I think the reality that testing of the type ASR conducts reveals is that the slope of the line is actually not monotonic at all, it's quite noisy, and in order to get good price / performance, you need data about the specific device in question, not just the price tag...!

If you think this is just a sour grapes concept invented by the poors, well, I'd say you're a snake oil salesman's ideal customer.

 

[YesChickenNuggets]

After Amir's power plant review, PS-audio has clearly been exposed as 90% snake-oil peddler. I wouldn't trust them with $5. There's nothing hifi about what they make, the fact that they cleared a product like that power plant for sale indicates they have zero integrity. These are bottom barrel engineers out here conning ignorant rich people, disgusting.

Companies such as PS audio drags down and are an embarrasment for the entire industry.

Their former customers should organize nothing short of a class action lawsuit, force them to buy their snakes back.

 

[ahofer]

Diminishing returns is a fictitious construct made up by those who cannot, or do not want to, afford spending more. As long as you choose wisely, you will always get better sound if you spend more. No one can quantify whether something sounds “2X” better. But we know it sounds better.

What I do not like about these speakers is the two crossover points in the most critical midband range. The crossover would have to be very well made and expensive to not have a detrimental affect on sound, and there’s no way that it is a this price point.

I’m sorry, but that’s nonsense. Have a look at the Chord Dave review, or the Audioquest Cable review. It’s perfectly possible, probable even, that the kilobuck stuff is worse than cheaper options.

And you might not want to get into a bank-account measuring contest here.

 

[verdun]

Chris, or some helpful person, is there an explanation in this thread of 'split magnetic gap' in he design of the woofers?
Does it mean two magnets with a gap between them? And what is the advantage of split magnetic gap? I was discussing it with an engineer and he wasn't sure enough to give me a definition of the term. TIA

 

[617]

Chris, or some helpful person, is there an explanation in this thread of 'split magnetic gap' in he design of the woofers?
Does it mean two magnets with a gap between them? And what is the advantage of split magnetic gap? I was discussing it with an engineer and he wasn't sure enough to give me a definition of the term. TIA

I think since magnets have constant flux throughout their geometry (I'm sure there are exceptions) the way driver engineers manipulate the force exerted by the magnet in different parts of the voice coil travel is by changing the geometry in a host of different ways, or by using separate magnets spaced out. See the diagram provided by JBL:

Transducers | JBL Professional Loudspeakers | English (US)

jblpro.com

Normally, the magnetic flux is strong in the center and weaker towards the edges, which means that the motor has less control over the motion of the cone at excursion extremes, leading to distortion. The dual magnetic gap creates a more even magnetic field for the voice coil to move through.

That's the conventional wisdom, anyway. Plenty of very good drivers use more ordinary magnet structures.

 

[Chris Brunhaver]

I think since magnets have constant flux throughout their geometry (I'm sure there are exceptions) the way driver engineers manipulate the force exerted by the magnet in different parts of the voice coil travel is by changing the geometry in a host of different ways, or by using separate magnets spaced out. See the diagram provided by JBL:

Transducers | JBL Professional Loudspeakers | English (US)

jblpro.com

Normally, the magnetic flux is strong in the center and weaker towards the edges, which means that the motor has less control over the motion of the cone at excursion extremes, leading to distortion. The dual magnetic gap creates a more even magnetic field for the voice coil to move through.

That's the conventional wisdom, anyway. Plenty of very good drivers use more ordinary magnet structures.

Part of the reason that I don't talk about the motor structure in a ton of detail is that it wasn't my original invention. I was something that my old employers from 20 years ago invented at a little company called Adire Audio. They called this approach XBL^2 and later just XBL. Attached is a little cutaway from our DC FEA. Basically, you have two top plates (with flux going in the same direction) and, as the coil moves it loses turns from one gap but gains them in the other, so the motor force stays constant over a broad range of stroke. Normally, when the motor force varies with excursion, the entire midrange of the woofer amplitude modulates with the bass signal, so the linear BL seems to really help.

Yes, there are multiple ways to optimize woofer motors but a lot of "ordinary magnet structures" aren't very symmetrical or linear in their motor force or inductance versus frequency/excursion/current and this is one of the main causes of distortion and poor sound quality in speakers. Here is a Klippel poster on that subject.

https://www.klippel.de/fileadmin/_migrated/content_uploads/Klippel_Nonlinearity_Poster.pdf

This forum has been pretty good about promoting advancements in this area, like the purifi drivers or this JBL that you mention, both of which are on the extreme end of the things that you can do to address some of these things. Even an LS50 woofer has a large ~2" coil with huge undercut pole and double shorting rings, which is quite exotic compared to most drivers.

That JBL motor differs compared to what we are doing because they're using a split in the backplate to form a second magnetic gap and hang a counterwound coil there, so it's a push/pull system. You can bias the coils apart and get a flatter BL (like the split gap approach). The did this on their WGTi series car woofers. The main benefit however is the how the opposite polarity coils minimize flux modulation and the symmetrical structure minimizes offset/rectification. Paradigm, Velodyne, Dali, Rockford Fosgate and other have used this strucutre with good results. I had considered it but, to get high excursion, the units become very deep and you need a second frame (and sometimes suspension) on the back of the motor to align things and the voice coil former becomes super long.

Purifi also uses a linear BL tech that wasn't their original invention (though they innovate in a lot of other areas and I've never seen this particular tech used in a midwoofer). Their technique was called LMS (linear motor system) by TC Sounds who originally patented it. The IP was later brought to Tymphany (who Carsten of Purifi was the CTO of). I don't know the exact licensing arrangements, but this is a very valid approach as well (though has somewhat negative implications for moving mass and inductance and gap width).

 

[617]

Chris, I don't know of a good resource to show people when it comes to speaker motors. This is an interesting topic and one which could help people understand some of the engineering that goes into high end drivers. I myself use CSS drivers which are XBL2 if I'm not mistaken and frankly the quality and quantity of bass they produce is totally excessive even at 10".

It would be really cool to see a history of speaker motors showing the advances of everyone from the Skaaning clan through to today.

What happened to TC Sounds anyway? Same fate as Adire and Aura?

 

[verdun]

Chris thank you for such a full explanation.

 

[CtheArgie]

The first post is over one year ago. PS people kept promising here “proper” measurements.

Where are they? They announced a smaller version and we still don’t have or can’t see measurements of the FR-30.

 

[NikJi]

@Chris Brunhaver - Thank you. I have been listening to your thoughts on the PSAudio youtube channel ever since you joined them. I can see the happiness in Paul’s eyes as he talks to you. He know he has landed a gem of a person to help move PSAudio to more respectable opinions amongst peers.

 

[fpitas]

I just the opposite.

I made mine modular, so I could carry the individual modules and stack them into a behemoth.

 

[Chris Brunhaver]

@Chris Brunhaver - Thank you. I have been listening to your thoughts on the PSAudio youtube channel ever since you joined them. I can see the happiness in Paul’s eyes as he talks to you. He know he has landed a gem of a person to help move PSAudio to more respectable opinions amongst peers.

Thanks! Yeah, he's been very supportive and I'm certainly trying to do something competitive and worthwhile product-wise. He wants me to do more youtube stuff and I need to prepare some design stuff or topics that people might enjoy.

 

[Chris Brunhaver]

Chris, I don't know of a good resource to show people when it comes to speaker motors. This is an interesting topic and one which could help people understand some of the engineering that goes into high end drivers. I myself use CSS drivers which are XBL2 if I'm not mistaken and frankly the quality and quantity of bass they produce is totally excessive even at 10".

It would be really cool to see a history of speaker motors showing the advances of everyone from the Skaaning clan through to today.

What happened to TC Sounds anyway? Same fate as Adire and Aura?

Fun fact, I did work for CSS (though not your 10" woofer), back when Bob Reimer owned it and later to help Dan and Kerry a little.

Well, there are a lot of inventions around motors that have been patented but also a lot of "trade secret" stuff and sometimes it's hard to know what designs used particular innovations because its not explicitly mentioned anywhere.

TC Sounds went bankrupt around 2008 and sold some IP in a banrupcy auction around then. Their "eclipse titanium" style frame design patents were picked up by Scott Atwell at Fi Car audio and the LMS patent by Tymphany. Thilo went on to work for Tianle (a main supplier of theirs) for a while and then for Tymphany, where he is still workingm AFAIK. Kyle Keating (whose name was on the LMS patent), hangs around the data-bass.com forum and Stephen Ponte went on to work for SVS and now JL Audio.

 

[617]

Fun fact, I did work for CSS (though not your 10" woofer), back when Bob Reimer owned it and later to help Dan and Kerry a little.

Well, there are a lot of inventions around motors that have been patented but also a lot of "trade secret" stuff and sometimes it's hard to know what designs used particular innovations because its not explicitly mentioned anywhere.

TC Sounds went bankrupt around 2008 and sold some IP in a banrupcy auction around then. Their "eclipse titanium" style frame design patents were picked up by Scott Atwell at Fi Car audio and the LMS patent by Tymphany. Thilo went on to work for Tianle (a main supplier of theirs) for a while and then for Tymphany, where he is still workingm AFAIK. Kyle Keating (whose name was on the LMS patent), hangs around the data-bass.com forum and Stephen Ponto went on to work for SVS and now JL Audio.

The high-excursion-speaker world strikes me as a very small community of engineers.

 

[Els]

"Diminishing returns is a fictitious construct made up by those who cannot, or do not want to, afford spending more. As long as you choose wisely, you will always get better sound if you spend more."

I certainly disagree with this, 100%. Good work on this site every day that proves the exact opposite!

This is a poor and inaccurate generalization. Some who can afford high priced gear but do not want to be suckers of the Hi Fi world, and by the way you can also get worst sound when spending more.

 

[MerlinGS]

I have not had a chance to read the full thread, so I'm not sure if anyone posted this, but HiFi News did some measurements (limited compared to what an instrument such as Klippel provides) of the speaker and the frequency response raises serious concerns (even though the chart provided is of poor resolution, it still shows the high-frequency increasing by 5 dB from 2.5kHz to 6 kHz). The reviewer loved the speaker (but that means little, considering what gets raves these days); however, I would imagine the speaker could be improved with a flatter frequency response (no off-axis/summary window measurements are provided, so no idea if it performs well here, thus allowing the user to properly eq the speaker). On the plus side, it does seem to have pretty decent distortion measurements (although it did exhibit some mild resonances at 72Hz, 107Hz, 185Hz, and 365Hz).